German Published Patent Appln. No. 10 2005 020 380 describes a fuel injection device, which is characterized by a noise-decoupling construction. The known fuel injection device includes a fuel injector, a receiving borehole for the fuel injector in a cylinder head and a fuel distributor line having a connection fitting. In this instance, the fuel injector is inserted into the connection fitting in a partially overlapping manner. The fuel injector is connected directly to the fuel distributor line via a connecting part, but is largely decoupled from the receiving borehole of the cylinder head. In one possible development, a pot-shaped sleeve is provided as the connecting part, which is situated securely and solidly on the downstream end of the connection fitting. The connecting part is developed in two parts, that is to say, it is made up of two semiannular ring elements. Each of the ring elements has a jacket section and a bottom section, the jacket section opposite the bottom section respectively transitioning into a hook-shaped latching section. The latching sections of the connecting part engage into two grooves on the circumference of the connection fitting. A middle opening is provided in the bottom section, through which a tapered region of the fuel injector penetrates, the tapered region having a conical edge as contact surface on the inlet fitting. A holding-down clamp is furthermore clamped between the bottom section of the connecting part and a shoulder on the fuel injector.
The development of the fuel injection device known from German Published Patent Appln. No. 10 2005 020 380 has the disadvantage that vibrations may be transmitted from the fuel injector to the connection fitting via the connecting part that is developed as a pot-shaped sleeve. Furthermore, the multi-part connecting part and the holding-down clamp must be suitably mounted together, which makes handling and especially mounting more difficult due to the multiplicity of the components involved.
Specifically in the case of electromagnetic high-pressure fuel injectors, which are used in Otto engines having direct injection, an obtrusive and disturbing contribution to the overall noise of the engine may occur, which may be described as valve ticking. Such valve ticking arises from the rapid opening and closing of the fuel injector, in which the valve needle is displaced in a highly dynamic way to the respective end stops. The impact of the valve needle on the end stops results in brief but very high contact forces which are transferred via a housing of the fuel injector to a fuel distributor rail in the form of structure-borne noise and vibrations. This results in a great noise generation.